Nickel Resistance Research Articles

Determinants Encoding Resistance to Several Heavy Metals in Newly Isolated Copper-Resistant Bacteria

Three copper-resistant, gram-negative bacteria were isolated and characterized. Of the three strains, Alcaligenes denitrificans AH tolerated the highest copper concentration (MIC = 4 mM CuSO(4)). All three strains showed various levels of resistance to other metal ions. A. denitrificans AH contains sequences which cross-hybridized with the mer (mercury resistance) determinant of Tn21 and the czc (cobalt, zinc, and cadmium resistance), cnr (cobalt and nickel resistance), and chr (chromate resistance) determinants of A. eutrophus CH34. DNA-DNA hybridization with probes prepared from A. eutrophus CH34 and Tn21 revealed the presence of chr-, cnr-, and mer-like sequences on the 200-kb plasmid pHG27 and of czc, cnr, and mer homologs located on the chromosome. The second strain, classified as Alcaligenes sp. strain PW, carries czc, cnr, and mer homologs on the 240-kb plasmid pHG29-c and a chr determinant on the 290-kb plasmid pHG29-a; a third plasmid, the 260-kb large plasmid pHG29-b, is cryptic. In contrast to the Alcaligenes strains, which were isolated from metal-contaminated water, Pseudomonas paucimobilis CD was isolated from the air. This strain harbors two cryptic plasmids: the 210-kb large plasmid pHG28-a and the 40-kb plasmid pHG28-b. Southern analysis revealed no homology between the metal ion resistance determinants of A. eutrophus CH34 and P. paucimobilis CD.

Nickel resistance of Alcaligenes denitrificans strain 4a-2 is chromosomally coded

A newly isolated aerobic hydrogen-oxidizing bacterium, Alcaligenes denitrificans strain 4a-2, differs from related autotrophic bacteria by containing only a single cytoplasmic, NAD-reducing hydrogenase, and by its high resistance to nickel ions, i.e. tolerance to 20 mM NiCl2. Strain 4a-2 harbors a single plasmid of about 250 kb. On helper-assisted mating of 4a-2 with Alcaligenes eutrophus strains H16,G29, and M85 nickelresistant transconjugants were selected; these did not contain the donor plasmid, however. All three transconjugants tolerated 3 to 10 mM NiCl2. The resistance was constitutively expressed. DNA/DNA hybridization showed homology with EcoRI-digested DNA of the wild type 4a-2 and transconjugants using a DNA probe containing nickel resistance genes of pMOL28. This indicated that the 4a-2 nickel resistance genes are located on the chromosome.

Linearization of a nickel resistance temperature detector and its application in temperature measurement

A theoretical study of a nickel resistance temperature detector (RTD) response linearization incorporating a new scheme, as well as conventional methods, is presented. The proposed scheme exhibits superior performance over conventional methods and offers linear temperature/voltage conversion over a wide dynamic range.

Cloning of pMOL28-encoded nickel resistance genes and expression of the genes in Alcaligenes eutrophus and Pseudomonas spp

The 163-kilobase-pair (kb) plasmid pMOL28, which determines inducible resistance to nickel, cobalt, chromate, and mercury salts in its native host Alcaligenes eutrophus CH34, was transferred to a derivative of A. eutrophus H16 and subjected to cloning procedures. After Tn5 transposon mutagenesis, restriction endonuclease analysis, and DNA-DNA hybridization, two DNA fragments, a 9.5-kb KpnI fragment and a 13.5-kb HindIII fragment (HKI), were isolated. HKI contained EK1, the KpnI fragment, as a subfragment flanked on both sides by short regions. Both fragments were ligated into the suicide vector pSUP202, the broad-host-range vector pVK101, and pUC19. Both fragments restored a nickel-sensitive Tn5 mutant to full nickel and cobalt resistance. The hybrid plasmid pVK101::HKI expressed full nickel resistance in all nickel-sensitive derivatives, either pMOL28-deficient or -defective, of the native host CH34. The hybrid plasmid pVK101::HKI also conferred nickel and cobalt resistance to A. eutrophus strains H16 and JMP222, Alcaligenes hydrogenophilus, Pseudomonas putida, and Pseudomonas oleovorans, but to a lower level of resistance. In all transconjugants the metal resistances coded by pVK101::HKI were expressed constitutively rather than inducibly. The hybrid plasmid metal resistance was not expressed in Escherichia coli. DNA sequences responsible for nickel resistance in newly isolated strains showed homology to the cloned pMOL28-encoded nickel and cobalt resistance determinant.

Nickel and cobalt resistance of various bacteria isolated from soil and highly polluted domestic and industrial wastes

Abstract From enrichment cultures in the presence of 1 mM NiCl2 200 strains of aerobic bacteria were isolated from 50 samples collected in the metal-processing industry, waste water treatment plants and from solid waste, highly polluted by heavy metals. The strains isolated were characterized with respect to their substrate spectrum and resistance to nickel, cobalt, zinc and cadmium salts and assigned to 21 groups. One representative of each group was described with respect to cell morphology. All strains were Gram-negative, non-sporing rods or cocci. The highest concentrations of nickel, cobalt, zinc, cadmium, copper, mercury, and silver allowing growth on solid media were estimated. Two strains were able to grow at 20 mM NiCl2 and CoCl2, one strain tolerated 12 mM and one 7.5 mM concentrations of these salts. Fifteen out of 21 strains contained at least one plasmid two contained two plasmids. The plasmid sizes varied between 50 and 340 kbp, except strain 10A, which contained a miniplasmid (2.6 kbp). Attempts to cure four selected strains by exposure to mitomycin C or growth at elevated temperature failed. By helper-assisted and unassisted conjugation the plasmids of strain 31A were shown to carry nickel and cobalt resistance determinants. Alcaligenes eutrophus strains H16 and N9A and denative of strain CH34 lacking one or both of its native metal resistance plasmids were used as recipients. Both plasmids, p TOM8 and pTOM9, of strain 31A carried resistance properties which were expressed in all recipients except. A. eutrophus H16, in which only nickel resistance was expressed. Plasmid pTOM3 residing in strain 10A could not be transferred as such. However, transconjugants derived from helper (pULB113)-assisted matings carried co-integrates of various sizes and were resistant to nickel and cobalt.

Characterization of a nickel resistant mouse cell line

Nickel is a potent carcinogen and, at high concentrations, is toxic to mammalian cells. The effects associated with nickel exposure are well-documented but its mechanism of action in the cell has not yet been fully described. In order to understand the metabolic fate of nickel in mammalian cells, a variant cell population has been selected that continues to grow and divide in the presence of nickel chloride concentrations that are toxic to the parental cell line (Balb/c-3T3 mouse fibroblasts). Nickel resistance is not caused by altered uptake of nickel from the medium or increased clearance from the cells and is not associated with changes in metallothionein expression. Compared to the normal cells, the nickel resistant cells have a decreased number of chromosomes and numerous centromeric fusions. The expression of some proteins and the distribution of nickel bound by various proteins are altered in the nickel resistant cells. Preliminary results indicate that the nickel resistant phenotype may be transferred by genomic DNA-mediated transfection into a recipient NIH-3T3 cell line. Current investigations are directed at identifying a gene responsible for nickel resistance.

Plasmids in the bacterial assemblage of a dystrophic Lake: Evidence for plasmid-encoded nickel resistance

Sixty-two aerobic bacterial strains isolated from the unproductive dystrophic Lake Skärshultsjön (South Sweden) were screened for plasmids. The lake is considered to be an extreme environment because of its high concentration of persistent but nontoxic humic compounds. One-third of the isolates harbored multiple plasmids usually of similar high molecular weights (>25 Mdal). The plasmid-bearing strains were members of the common aquatic taxaPseudomonas spp.,Acinetobacter sp.,Alcaligenes sp.,Aeromonas/Vibrio group, andEnterobacteriaceae (taxonomy is tentative). The majority of isolates displayed multiple resistance to antibiotics and heavy metals. Some of them were capable of degrading aromatic compounds. Three isolates were chosen for curing experiments. Only strain S-68, anAlcaligenes sp., could be cured of one of its two plasmids. It harbored the two cryptic plasmids pQQ32 and pQQ70 of 32 and ca. 70 Mdal, and the latter was segregated during ethidium bromide treatment. Parental strain S-68 was capable of degrading some of nonchlorinated phenolic compounds and displayed resistance to a broad spectrum of antibiotics and the heavy metals Co(2+), Ni(2+), Zn(2+), Cd(2+), and Hg(2+). Derivative strain S-68-41 lost its resistance to nickel, suggesting segregated plasmid PQQ70 coded for nickel resistance. Transformation experiments to restore nickel resistance in the cured derivative strain were not successful.

Inducible and constitutive expression of pMOL28-encoded nickel resistance in Alcaligenes eutrophus N9A.

The nickel and cobalt resistance plasmid pMOL28 was transferred by conjugation from its natural host Alcaligenes eutrophus CH34 to the susceptible A. eutrophus N9A. Strain N9A and its pMOL28-containing transconjugant M220 were studied in detail. At a concentration of 3.0 mM NiCl2, the wild-type N9A did not grow, while M220 started to grow at its maximum exponential growth rate after a lag of 12 to 24 h. When grown in the presence of subinhibitory concentrations (0.5 mM) of nickel salt, M220 grew actively at 3 mM NiCl2 without a lag, indicating that nickel resistance is an inducible property. Expression of nickel resistance required active growth in the presence of nickel salts at a concentration higher than 0.05 mM. Two mutants of M220 were isolated which expressed nickel resistance constitutively. When the plasmids, pMOL28.1 and pMOL28.2, carried by the mutants were transferred to strains H16 and CH34, the transconjugants expressed constitutive nickel resistance. This indicates that the mutation is plasmid located. Both mutants expressed constitutive resistance to nickel and cobalt. Physiological studies revealed the following differences between strain N9A and its pMOL28.1-harboring mutant derivatives. (i) The uptake of 63NiCl2 occurred more rapidly in the susceptible strain and reached a 30- to 60-fold-higher amount that in the pMOL28.1-harboring mutant; (ii) in intact cells of the susceptible strain N9A, the cytoplasmic hydrogenase was inhibited by 1 to 5 nM NiCl2, whereas 10 mM Ni2+ was needed to inhibit the hydrogenase of mutant cells; (iii) the minimal concentration of nickel chloride for the derepressed synthesis of cytoplasmic hydrogenase was lower in strain N9A (1 to 3 microM) than in the constitutive mutant (8 to 10 microM).

Plasmid pMOL28-mediated inducible nickel resistance inAlcaligenes eutrophusstrain CH34

The effect of nickel salt on growth of the nickel-resistant wild type strain Alcaligenes eutrophus CH34, which harbours two plasmids, and on its partially or totally cured derivatives as well as of the wild type strain H16 was studied. Plasmid pMOL28-mediated nickel resistance turned out to be an inducible property. Full resistance is induced during growth in the presence of 0.03–3.0 mM NiCl2. Induction requires growth. While plasmid-free cells accumulate nickel at a high rate, the pMOL28-harbouring-induced cells accumulate only negligibly small amounts of nickel. It is concluded that pMOL28 mediates a protective mechanism preventing the cells to accumulate nickel ions intracellularly at toxic concentrations.

Plasma calorimeter for absorption measurement of laser produced plasma

A new type of plasma calorimeter has been developed for laser light absorption and measurement of laser irradiated targets. The principle of this detector is the same as a bolometer; plasmas and x rays are absorbed by a thin glass plate which is transparent enough for laser light, and temperature rise of the absorber plate is detected by a faint increase of the resistance of a nickel resistance bulb. The structure and application example are described.

Linearization of the characteristic of a nickel resistance thermometer

Linearization of the characteristic of a nickel resistance thermometer

Climate in a Glasshouse (1)

As a preliminary to the study of microclimatic conditions in a glass or vinyl house, comprehensive measurements were made in a closed glasshouse of Natl. Inst. of Agric. Sci. during a relatively long period from Nov. 1966 to April 1967. Ten ventilated nickel resistance dry and wet bulb thermometers were used to measure temperature and humidity in the glasshouse. The data used in this paper were extracted from the charts by visually determining 30-min, means. The results obtained may be summarized as follows:(1) The diurnal change of temperature inside the glasshouse was in phase that of the air temperature measured at the height of 130cm in the enclosure. This was mainly due to the small heat capacity of the glasshouse.The difference in the maximum air temperatures between inside and outside the glasshouse increased proportionally with increasing solar-radiation. This relationship may be used in predicting the maximum air temperature inside the glasshoue from the climatic data of air temperature and of solar radiation(2) The minimum temperatures inside the glasshouse were almost always about 1-2°C higher than those measured at the enclosure. The difference of the minimum air temperatures between inside and outside the glasshouse reported by YABUKI (1961) was slightly larger than that presented in this paper. On comparison, the results from a simple conventionl way (iTmax+iTmin)/2 turned out to be larger by about 10 percent than those calculated from thirty minutes averages.(3) The fall of air temperature inside the glasshouse during the night was found to be closely related to two factors of the night fall of the outside air temperature and of long-wave net radiation. The temperature of inside surface of the glass was estimated by a radiation balance equation in the glasshouse. From the results it followed that on a clear night the temperature at inside surface of the glass wall was lower by about 6-7°C than that of the floor surface in the glasshouse, implying that the temperature at the inside surface was equal to the air temperature outside the glasshouse.(4) An equation relating air temperature conditions in a glasshouse to outside meteorological conditions and to the glasshouse structure was obtained by considering heat balance of the glasshouse. The daily mean and daily amplitude of the air temperature inside the glasshouse were compared respectively with empirical relationships obtained in this report.

Thin-film resistance thermometer for registering the surface temperature of a powder at high heat transfer rates

1. A method has been developed for preparing thin (0.5 μ) nickel films by electrolytic deposition. These films can be used as resistance thermometers for registering the surface temperature of powder specimens at high heat transfer rates. 2. The thin-film nickel resistance thermometers thus obtained were calibrated in the range 0–300° C using a static method. 3. A three-channel amplifying thermometric bridge has been designed and built. This bridge has a sensitivity of 0.025 mA/ohm and a passband of more than 10 kHz at a nonlinear distortion coefficient of less than 0.5% (for each channel). 4. Preliminary experiments have been conducted on the ignition of ballistite N powder+carbon black using a film-resistance thermometer to register the surface temperature.

A Fundamental Study on the Control of Glasshouse Plant Environment (1)

A 1/5 scale controlled glasshouse in the Phytotron of Kyushu University has been used for the present study.Aspirated nickel resistance thermometers have been used for measuring outside dry and wet temperatures and thermocouples for measuring temperatures in the concrete floor. For studying the radiation conditions in the glasshouse, we measured the net radiation and the solar radiation on the floor by a net radiometer and a Moll-Gorczynski solarimeter, and the solar radiation of the outside by a Moll-Gorczynski solarimeter. The volume of air which flowed in the glasshouse was measured by an orifice flow meter. We devised methods for the measurement of air temperatures in the glasshouse and surface temperatures of the glass roof inside and outside by the use of thermocouples.Interesting results which were obtained by this investigation are as follows:1) As to the amount of light transmitted, we found that there was clear difference of the transmission coefficient between the direct solar radiation transmitted through the ceiling and the wall (See in Fig. 1). Therefore, we would like to propose the concept of the glasshouse coefficient.2) The main diagram of energy exchange in the glasshouse is shown in Fig. 3, in which Qf is the total heat from the glasshouse floor, Qa is the heat gained by the glasshouse air, Qv is the heat due to glass temperature variation, Qrg0 is the net radiation on the outside glass surface, Qhg0 is the heat transmitted from the glass surface to the air surrounding the glasshouse. The amount of heat Qf is very large, so the main energy exchange of glasshouse takes place at the floor.3) During the night, the value of Qrg0 becomes greater.On another occasion we would like to study the biological significance of this phenomenon.

Measurement of Temperature and Humidity in Tobacco Plots in Rhodesia

Small nickel resistance thermometers were tested in various anti-radiation screens over bare sandy soil in Southern Rhodesia. Satisfactory results were obtained only when the thermometers were aspirated in small chromed metal shields, based on the design of the Mark 3 Assmann psychrometer. The aspirated units were compared with an Assmann, at various heights within tobacco plots during a range of whether conditions, and grave satisfactory results when used for continuous periods of several months. Some results are presented illustrating the vertical distribution of temperature and humidity within tobacco plots at different stages of growth. When plants were small, temperature and humidity gradients appeared to be similar to those that might be expected over open ground. Later the pattern resembled that of a crop of medium ground cover and density.

Instruments for micro‐meteorology

AbstractSeveral instruments suitable for long‐term recording of temperature, humidity and wind gradients among growing crops have been constructed. Practical details are given of the use of thermistors and miniature nickel resistance thermometers as wet‐ and dry‐bulb psychrometers, and of the use of these units for direct recording of both dew point and dew‐point gradient. Modifications of the sensitive cup anemometer, appropriate circuits and details of a ‘hot‐bulb’ anemometer using a resistance thermometer, are described.

Portable Precision Resistance Thermometer Equipment for Mains Operation

Nickel resistance thermometers have been designed for clinical use, together with a portable mains-operated resistance bridge of the Callendar-Griffiths type. An accuracy of ±0.02° F. (±0.01° C.) is claimed.

Automatic Gas Analysis Recorder for the Range of 0 to 35 per cent of CO_2 in Air

An automatic instrument for recording the percentage of carbon dioxide in air supplied to greenhouses for experimental work is described. The instrument gives a record over the range of 0–3.5% carbon dioxide. The application of the thermal conductivity method of gas analysis is described, and several new features not heretofore found in such apparatus are discussed.Convection Type Thermal Conductivity Cell.—A cell construction is described which renders the indications of gas concentration independent of the velocity of flow through the sampling line. The circulation of gas through the cell is dependent on the platinum wire temperature only.Compensation for Variations in Bridge Current.—A method is described for compensating the thermal gas analysis Wheatstone bridge for variations in the bridge current by introducing a manganin resistance in series with one of the cell wires.Compensation for Variations in Cell Temperature.—A method is described for compensating the bridge for variations in cell temperature by introducing a nickel resistance in one of the bridge arms.The results obtained with this instrument indicate that it is accurate to 0.05% of carbon dioxide, over the range of 0–3.5% carbon dioxide. The application of similar gas analysis bridges and recorders to the analysis of other gas mixtures where the same range of thermal conductivity differences is involved is discussed.

A New Relative Humidity Recorder

Recorder Mechanism.—A mechanism is described capable of automatically balancing any network of impedances where the balance point is attained by the motion of one or more sliders along slide wires, and where the balance point is determined by the absence of current in the recorder galvanometer.Relative Humidity Curves.—From the formula for relative humidity in terms of the wet and dry bulb temperatures, it is shown that for constant humidity the relation between wet and dry bulb temperatures is very nearly a linear one, and that the value of the humidity is uniquely defined by the ratio (wet bulb temp.—A)/(dry bulb temp.—B) where B is a constant and A is a function of the relative humidity but changes only slightly with it.Recorder Circuit.—By using a nickel resistance thermometer in a network which is essentially a split circuit potentiometer, it is possible to secure a potential difference across the ends of a slide wire which is directly proportional to (dry bulb temp.—B). In another very similar circuit a potential difference is gotten which is proportional to (wet bulb temp-A). This latter potential difference is automatically balanced against a portion of the former by the recorder mechanism mentioned above, and the position of balance is indicative of the ratio (wet bulb temp.—A)/(dry bulb temp.—B) so that the instrument reads directly in relative humidity.The results of a check on the finished instrument are given from which it appears that the approximations made in the design and any inaccuracies introduced in the actual construction are of no greater magnitude than the uncertainties in the humidity formula itself.Maintenance of Wet Bulb.—Two forms of wet bulb are described which are capable of continuous operation. In one the customary wick is replaced by a spray, and in the other a long wick is provided so that a clean portion can be substituted for the soiled part merely by turning a roller to wind the wick from one holder on to another.